1. Field of the Invention
The present invention relates to an air feeding apparatus, more particularly one, which can be controlled to change temperature of air supplied from it according to needs.
2. Brief Description of the Prior Art
In early time when air conditioners were not available, electric fans were used to increase ventilation to reduce high temperature in the summer, and stoves were used to produce heat in the winter. Nowadays, air conditioners and electric heating devices are easily available, and many large buildings are equipped with central air conditioning systems therefore people live in a more comfortable environment from the point of view of temperature control.
However, performance of electric fans is significantly reduced in hot weather. And, air conditioners are relatively expensive, and cannot be carried. In addition, central air conditioning systems are only suitable for large buildings such as hospitals and commercial centers.